2
For length of days, and long life, and peace, shall they
add to thee.

3
Let not mercy and truth forsake thee: bind them about thy
neck; write them upon the table of thine heart:

A beautiful proverb about mercy and
truth.

On how merciful unbelievers are, see John 15:12.
On the quest for truth, it's a bit rich coming from someone whose
whole endeavor is to find mistakes in the Bible, and leaves no stone
unturned such as disregarding context, to find them, chapter 1:26.

4
So shalt thou find
favour and good understanding in the sight of God and man.

5
Trust in the LORD with all thine heart; and lean not unto thine own
understanding.

And there we go, mercy and truth are already forgotten,
verse 3. We have to be as merciless as possible when
reading the Bible.
The Bible doesn't stay that one should not make an attempt at
understanding, this verse actually indicates we should, but we should
not lean on them, turning what we think into our gods. If we would
trust scientists, we would have believed that the Piltdown
Man, Nebraska
Man and Lucy were all missing links. But the Bible says there is
no such thing, and all these previously heralded missing links are now
relegated to the clearly ape branch.
Or take another famous scientist: Stephen Hawking. If
you have leaned on him in 1988, you would have believed that only
scientists were really able to give the answer to why we and the
universe exists:

However, if we do discover a [unified] theory ... it would be
the ultimate triumph of human reason — for then we would know
the mind of God.

Some people will be very disappointed if there is not an
ultimate theory, that can be formulated as a finite number of
principles. I used to belong to that camp, but I have changed my
mind.

Stephen Hawkins admits we cannot know the mind of God... This
verse is of course not only about scientific knowledge. It is in
particular about moral knowledge: what is good and what is bad? How
surprising is it if scientists tell us that we came here by survival
logic: only the fittest survived, it's by weeding out the weak that
advances were made, and people start acting on that logic? And it's
not only the Columbine school killers with the text “Natural
selection” on their T-shirts, but it happens
also in Finland:

I am a social
Darwinist ... There are no other universal laws than the laws of
nature and the laws of physics. ... Evolution is both a theory and a
fact, creationism is neither one. It’s time to put natural selection
& survival of the fittest back on track!’

Just accept what your science teacher tells you?

6
In all thy ways acknowledge him, and he shall direct thy
paths.

7
Be not wise in thine own eyes: fear the LORD, and depart from evil.

8
It shall be health to thy navel, and marrow to thy bones.

9
Honour
the LORD with thy substance, and with the firstfruits of all thine increase:

(3:9-10)
If you give money to God, he will make you rich and you'll have
lots of wine.

Yes, giving to God seems to have a different effect than
paying taxes. And God only asks for ten percent.

10
So shall thy barns be filled with plenty, and thy presses shall burst
out with new wine.

11
My son, despise not the chastening of the LORD; neither be weary of his
correction:

12
For whom the LORD loveth he correcteth; even as a father
the son in whom he delighteth.

13
Happy is the man that findeth wisdom, and the man
that getteth understanding.